It was actually last November that the singer debuted her slimmer figure when she wore a plunging Robert Cavalli dress at the 47th annual Country Music Awards.

"I have been working out a lot! Working out and drinking juice and just running, running around," Lambert told E! News at the time.

She added, "I fluctuate all the time in my weight—it's really annoying—but I'm going to be 30 in like four days, so I'm like, 'I need to get ahead of this thing!' Because they say when you hit 30 it doesn't get easier. So I thought, 'Well, you know, if I get a little healthier before I turn 30, maybe I can get ahead of the game.'"

Shortly thereafter, Lambert also blasted "ridiculous" tabloid reports that claimed she had undergone some sort of surgery.

"I lost my weight the healthy and good old fashioned way," Lambert wrote, in part, on her official website. "Watching what I eat and working out."